Brake



A. Y. DODGE Sept. 26, 1933.

BRAKE Filed oct. 12, 1928 2 Sheets-Sheet l llllllllll ll llllllllll llllllllll M. 4 M A.

.noo mum F mlm IN VEN TOR. diez Y @vflgw A TTORNEY Sept.. 26, 1933. A. Y. DODGE 1,928,051

BRAKE Filed Oct. l2, 1928 2 Sheets-Sheet 2 s a M se I "r2-:1mm ,l 6

INVENTOR.

Awel Ymlgw ATTORNEY .atented Sept. l26, 1933 i 1,928,05

UNITED STATES PATENT OFFICE BRAKE Adiel Y. Dodge, South Bend, Ind., assigner to Bendix Brake Company, South Bend, Ind., a corporation of Illinois Application October 12, 1928. Serial No. 312,039

15 Claims. (Cl. 188-79.5)

'I'his invention relates to brakes, and is illusan internal expanding brake of a Well-known trated as embodied in an internal expanding three-shoe type, and includes a rotatable drum brake for an automobile. An object of the in- 10, at the open side of which is a support `such vention is to provide a readily-adjusted guide as a backing plate 12, and within which is arfor a portion of the brake friction means. ranged the friction means of the brake. AThe 65 In one desirable arrangement, the novel guidfriction means of this particular brake includes ing means controls a portion of the friction a primary or servo shoe 14, unanchored and conmeans, for example an unanchored friction shoe nected by means such as a oating pivot 16 having an operative connection with another to a secondary shoe 18 pivoted on a xed anchor shoe which may engage an anchor taking the 20, together with an auxiliary shoe 22 mounted 70 torque of both shoes. The present invention reon a fixed pivot or anchor 24. As shown in lates to the adjustment of a guide of this char- Figures 6 and 8, the shoes may, if desired, be acter, or of an equivalent positioning device, formed by welding together Several Separatelypreferably by means such as a spring acting formed steel stampings to give va generally under the control of an operator, by releasing T-shaped construction with a stiffening web ap- 7,

a clamping or holding device which permits the proximately in the center of the shoe. operation of the spring and which is then again The brake is applied by means such as a doutightened to preserve the adjustment permable cam 26 acting on U-shaped reinforcing memnently. The spring may also, if desired, be utibers 28 doubled over the ends of the stiifening lized as a return spring for the brake. webs of shoes 14 and 22, the cam acting against 80 Inthe particular arrangements illustrated, the .the resistance of a main return spring 30. A

c shoe and the guide member are interconnected steady rest 32 is shown adjacent the unanchored by means of the pin-and-slot type, the guide end of .shoe 18. member being pivoted so that the spring moves According to the present invention, the shoe it to adjusted position with the brake applied, 14, or an equivalent partof the friction means of 85 whereupon the guide plate is clamped permaa brake of some'other type, is provided with novel nently in place to preserve the adjustment, and readily adjustable guiding means, prefer- Ordinarily this is a factory adjustment and will ably acting in a general way like the guide denot require resetting until new shoes are inserted scribed and claimed in prior application No.

in the brake after long use has worn out the 233,754, led jointly by myself and Roy S. San- 90 original set. ford.

The above and other objects and features of In the arrangement of Figure 1, the web of the invention, including certain particular strucshoe 14 is formed with a guide or cam slot or tures especially suited for this adjustment, and opening 34, embracing laterally-extending pro- 35 various novel and desirable details of construcjections 36 on a stamped steel arm 38 mounted 95 tion, will be apparent from the following deon the backing plate by means of a clamping bolt scription of the illustrative embodiments shown or pivot at its lower end. A coil spring 42 in the accompanying drawings, in which: is preferably tensioned between the lower pro- Figure 1 is a vertical section through the brake, jection 36 and the unanchored end of shoe 18.

40 just inside ,the head of the brake drum, and This serves as an auxiliary return spring, against 100 showing the brake shoes in side elevation; the resistance of which shoe 18 is applied; it Figure 2 is a partial section on the line 2--2 also, however', serves as means for automatically of Figure 1, showing one form of guide; adjusting the positioning device 38.

Figure 3 is a partial section on the line 3-3 In the manufacture of the brake, after the Y of Figure 1, showing the connection between two various parts are assembled and adjusted, bolt 105 of the shoes; 40 is loosened and the brake is applied. The

Figure 4 is a partial section on the line 4-4 shoe 14 moves to its applied position, and also of Figure 1, showing the relation of the brake forces shoe 18 to applied position aaginst the cam to the guide openings; resistance of spring 42, while at the Sametime v Figure 5 iS a partial Veltloal Section, COrrethe lower projection 36 is held yieldingly against 110 sponding to the left portion of Figure 1, but the lower edge of opening 34 by the spring 42.

Showing a mded form Ofllide; With the brake held so applied, bolt 40 is tight- Fgure 6 S a partial SeCtlOn 0n the line 6--6 ened again to preserve the adjustment of device of Figure 5, showing the modified guide; 33 so made,

Figure I is a partial Section, Corresponding to Whenever the brake is applied thereafter, the 115 Figure 5, but ShOWmg a thll'd form 0f guide; paths of movement of shoes 14 and 18 are conand trolled and predetermined by anchor 20, pivot Figure 8 is a partial section o'n the line 8-8 16, and by the lower edge of opening 34 riding or of Figure 7, and showing the third guide. cammingr against the lower projection 36. Pref- The brake illustrated in all of the gures is erably this lower edge is inclined at such an 120 angle that shoes 14 and 18 engage the drum substantially simultaneously, although this is not essential, as the object of'the guide is rather to control shoe 18 so that it will not be forced suddenly againstH the drum as shoe 14 takes hold. with a snapping or jarring action.

Upon release of the brake, spring 42 functions to draw the secondary shoe 18 bodily upward, also aiding spring 30 in drawing shoe 14 circumferentially of the drum the slot 34 at its j upper edge abutting the upper projection 36 of a laterally-projecting guide pin 52, on which a slot 34.

the arm 38. The upper projection 36 thus serves .as a stop determining the released position of the shoe 14.

If desired, bolt 40 may be extended through an opening 46 in the web of shoe 14, and provided with washers 48 held by means such as a cotter pin 50, thus forming a steady rest for the shoe. j

. In Figures 5 and 6, shoe 14 is provided with roller 54 may be mounted, the guide or cam slot 56 being in a member 58 corresponding to the arm 38. Member 58 is held by two clamping bolts 69, about the upper one of v.which it is pivoted by spring 42 when the bolts are loosened and the brake is applied, to make the adjustment as described above, the bolts then being tightened again as before.

In Figures 7 and 8, the slot 34 isin the shoe web as in'Figure 1, but embraces a separate pin 64 on a triangular lever member 66 held by two clamping bolts 68 arranged in a line paralleling In this arrangement, with the bolts loosened and the brake applied, member 66 swings about the upper bolt 68 to adjusted position, whereupon the bolts are tightened. Pin 64 may have Washers '70 embracing the shoe web and held by a coil spring 72 compressed by a third washer 74 held by meanssuch as a cotter pin 76, thus forming a steady 1est.

While several illustrative embodiments have been described in detail, it is not my intention to limit the Vscope of the invention to those particular embodiments, or otherwise than by the terms of the appended claims.

I claim:

1. A brake having, in combination, .friction means, a guide comprising afpivoted lever having a part slidably guided and engaged by a portion of the friction means throughoutthe operationof applying the brake, means for adjusting the position of said guide by shifting thev lever angularly about its pivot while the friction means is in applied position, and means for holding the guide in adjusted position.

2. A brake having an angularly-adjustable positioning device, in combination with a spring for actuating said device to adjust its position.

3. A brake having friction means and an angularly-adjustable positioning device, in combination with a spring for swinging said device to a position determined by the applied position of the friction means, to adjust the position of said device. Y

4. A brake comprising, in combination, friction fneans, a positioning device for the friction means, and a spring tensioned between the positioning device and a portion of the friction means the position of said device.

5. A brake comprising, in combination, friction means, a positioning device for the friction means, and a spring serving as a return 'spring for a portion of the friction means and also serving to adjust the position of' said device.

. 6;A positioning device for a brake comprising an arm adapted to be pivoted at one end and having a laterally-projecting guide at the other end, in combination with a spring acting on said other end and means holding said arm against the action of said spring.

7. A brake having at least two shoes connected by' a oating joint, in combination with an adjustable guide for oneshoe acting on the other shoe through said joint, together with spring means for shifting said guide to adjusted position when the shoes are in applied position.

8. A brake having at least two shoes connected by a floating joint, in combination with an adjustalole guide for one shoe acting Aon the other shoe through said joint, together with spring means for shifting said guide to adjusted posi-Y tion when the shoes are in applied position, and means for securing the guide in said adjusted position and holding it against the tension of said means.

9. A brake having at least two shoes connected by a iioating joint, in combination with an adjustable guide for one shoe acting on the other shoe throughk said joint, Vtogether with spring means for shifting said guide to adjusted position when the shoes are in applied position, said spring means also serving as a return spring for at least one of the shoes.

10. A positioning device for a brake formed with an inclined guide slot and provided with two clamping bolts.

11. A positioning device for a brake formed with an inclined guide slot and provided with two clamping bolts, in combination with a spring urging said device about one of thel bolts as a pivot.

12. A brake comprising, in combination', a pair of shoes, one of which acts on the other and one of which has a laterally-extending projec= Ation, and a part adjacent said latter shoe which has a guide slot extending in the direction of brake-applying movement of said projection and which slot embraces said projection.

13. A brake comprising, in combination, a pair of shoes, one of which is anchored, the unanchored one of which acts on the anchored shoe and the unanchored one of which has a guide projection, and a part adjacent the unanchored shoe which has a guide slot extending in the direction of brake-applying movement of said projection and which slot embraces said projection.

14. A brake comprising, in combination, a pair of shoes, one of which is anchored, the unanchored one of whichcts on the anchored shoe and the unanchored one of which has a guide projection.' and a part adjacent the unanchored shoe which has a' guide slot extending in the di rection of brake-applying movement of said projection and'which slot embraces said projection,

openings on a line approximately paralleling said slot and formed with means for the attachment of a spring.

ADIEL Y. DODGE. 

